Global existence of a weak solution of the incompressible Euler equations with helical symmetry and Lp vorticity

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPERJ - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOWe prove the global existence of a helical weak solution of the 3D Euler equations, in full space, for an initial velocity with helical symmetry, without swirl, and whose initial vorticity is compactly supported in the axial plane and belongs to L-p, for some p > 4/3. This result is an extension of the existence part of the work of B. Ettinger and E. Titi [9], who studied well-posedness of the Euler equations with helical symmetry without swirl, with bounded initial vorticity, in a helical pipe.We prove the global existence of a helical weak solution of the 3D Euler equations, in full space, for an initial velocity with helical symmetry, without swirl, and whose initial vorticity is compactly supported in the axial plane and belongs to L-p, for some p > 4/3. This result is an extension of the existence part of the work of B. Ettinger and E. Titi [9], who studied well-posedness of the Euler equations with helical symmetry without swirl, with bounded initial vorticity, in a helical pipe.641309341CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPERJ - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPERJ - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPq [306331/2010-1, 303089/2010-5, 236994/2012-3]FAPESP [2007/51490-7, 05/58136-9]306331/2010-1; 303089/2010-5; 236994/2012-3E-26/103.197/20122007/51490-7; 05/58136-

Analog SiPM in Planar CMOS Technology

Silicon Photomultipliers (SiPMs) are emerging single photon detectors used in many applications requiring large active area, photon number resolving capability and immunity to magnetic fields. We developed planar analog SiPMs in a reliable and cost-effective CMOS technology with a total photosensitive area of about 1×1 mm2. Three devices with different active areas, and fill-factor (21%, 58.3%, 73.7%), have been characterized. The maximum photon detection efficiency is in the near-UV and tops at 38% (fill-factor included), with a dark count rate of 125 kcps. Gain and crosstalk depend on the active area size and are comparable to those of commercial best-in-class custom-technology SiPMs. However our full CMOS processing enables advanced SiPM single-chip systems where transistors and further on chip electronics can be integrated together with the detectors

Managing Polyploidy in Ex Situ Conservation Genetics: The Case of the Critically Endangered Adriatic Sturgeon (Acipenser naccarii)

While the current expansion of conservation genetics enables to address more efficiently the management of threatened species, alternative methods for genetic relatedness data analysis in polyploid species are necessary. Within this framework, we present a standardized and simple protocol specifically designed for polyploid species that can facilitate management of genetic diversity, as exemplified by the ex situ conservation program for the tetraploid Adriatic sturgeon Acipenser naccarii. A critically endangered endemic species of the Adriatic Sea tributaries, its persistence is strictly linked to the ex situ conservation of a single captive broodstock currently decimated to about 25 individuals, which represents the last remaining population of Adriatic sturgeon of certain wild origin. The genetic variability of three F1 broodstocks available as future breeders was estimated based on mitochondrial and microsatellite information and compared with the variability of the parental generation. Genetic data showed that the F1 stocks have only retained part of the genetic variation present in the original stock due to the few parent pairs used as founders. This prompts for the urgent improvement of the current F1 stocks by incorporating new founders that better represent the genetic diversity available. Following parental allocation based on band sharing values, we set up a user-friendly tool for selection of candidate breeders according to relatedness between all possible parent-pairs that secures the use of non-related individuals. The approach developed here could also be applied to other endangered tetraploid sturgeon species overexploited for caviar production, particularly in regions lacking proper infrastructure and/or expertise